U.S. Education Secretary Arne Duncan says "far too many effective educators" are leaving the field early, and part of the problem is a lack of opportunities to make their voices heard.

Duncan made his remarks in an online video for the Leading Educators conference taking place in New Orleans this week. More than 350 teachers are meeting as part of a two-year fellowship.

"All across the country, we must do a better job of leveraging the teaching talent within our nation's classrooms," Duncan said. "No one wants to stay in a job where they feel unsupported or unable to advance in the profession and still do what they love."

A persistent complaint among teachers is that they don't have the ability to shape major changes in education - unless they stop teaching and take on administrative jobs.

As a partial solution, Duncan proposed creating new roles for teachers that let them continue to work with children in the classroom "while being an integral part of educational improvements" locally and nationally, with "regular opportunities to give feedback" to the administrators who are changing policy.

When that happens, "they are more likely to value their work, and to stay in the profession and to feel supportive, and effective teacher leadership has been shown to produce better outcomes for our nation's students," Duncan said.